why do you get more mpg from shell than asda and tesco
my mate swear blind he get 100 miles more from useing shell petrol than asda and i asked another pal to try it and told me got got 84 miles more per tank .

eh? really?! only got tesco and morrisons withing about 30 miles of mine...
surely it can't be right? seems unlikely

is it because they have saved that much money and the extra weight of the coings is takink it toll.

They would need to take the same trip same conditions etc to get a fair picture ie same motorway miles, standing traffic etc, it could be that shell has a higher octane rating ? is it like for like petrol as you can buy the higher octane stuff and they more or less gurantee an improved mileage per gallon

whoops spelling again time for bed me thinks

isnt it cause shell petrol is better quality, so the car runs more efficiently?
i remember seeing an article on it once where they used vpower for a while on 3 different cars, and it showed before and after pics of the valves, all three were much cleaner after using it...

I had an MR2 turbo, definately better MPG on optimax and it allowed more boost compared to 97 ron.

On an N/A car..... not really noticed any difference myself.

Your engine needs to adjust the timing to make the most of higher octane fuel otherwise there'll be little/no difference.
Anything with a knock sensor will do it, almost all turbocharged engines for a start

quote:

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Originally posted by UncleFista
Your engine needs to adjust the timing to make the most of higher octane fuel otherwise there'll be little/no difference.
Anything with a knock sensor will do it, almost all turbocharged engines for a start

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WOuld also depend if he is measuring this as 20 Liters of Each type of fuel or £20 worth of fuel...

I tend to get better mpg in the jag with shell than asda or sainsbury (cant use tesco as the car runs bad on it). I havnt tried the astra yet but that is because the nearest shell to us is 20 miles away.
I think it has something to do with the additives the supermarkets add to their fuel to make it last longer. Its another way for the supermarkets to make more £££'s

I noticed a bit more power from the shells performance fuel in the bluebird, so I suppose I could back off the throttle a bit and same money, but since its on LPG now it's all a bit irrelevant.

quote:

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Originally posted by speedyxjsI think it has something to do with the additives the supermarkets add to their fuel to make it last longer.

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think he's meaning cheap booze, hic! rather than detergents

I think these extra mpg stories are urban myths, it definitely is with diesel fuels which have been shown to give the same results from cheapest to premium brands.

I've driven diesels for that long I can't really comment on petrol any more. In my diesel experience the only difference between brands of fuel is the price. Performance and mpg seem consistent in the 306HDI, Leon TDI and Passat TDI I have run/am running.

I had the Indy (2.0 Pinto) tuned by Tom Airey who recomended Tesco 99RON or Shell Optimax for best results. I use Tesco 99RON because it's nearer, cheaper and I get the loyalty points. Car runs very well on it too.

I cant comment for across the water, but over here in northern ireland The fuel all comes from the same gantries as the major players..

I know this because I worked for the company that delivered it for tescos..

Some mag that I have got did a comparison and there was a difference; need to dig out hte article.....

Right!....
I have proof of over 104,000 miles (and 13 years doing it in the same vehicle)

My Land Rover, did between 1.1 and 2.8Mpg better on Shell Diesel.
Now that does not sound a lot, especially on a 2 ton Landy (LWB 12 seater with Roll cage and roofrack).

However, the Real gain is NOT obvious.

Shell nearly always cost me 1p per litre MORE than Asda Tesco etc.

OK.. so here is the maths:
Thats 4.5p per gallon more.

With the Landy it was costing me about 14p per mile. So 1.1 Miles extra saved me about 16p, less the 4.5p extra paid for Shell... The saving was about 12p per gallon.
At best (depending on my driving) 2.8miles was worth 39p less the 4.5p extra paid out. Thus 34p per gallon saved
This saving was anything between 12p and 34p per gallon.

If you see petrol at 1p per litre (4.5p per gallon) you think its a saving.

However, by Paying out a little extra for Shell, I could save upt to 34p per gallon.
Thats a real saving, but not obvious when you look at the pump prices.

I can also say that Esso, and Texaco were also fairly good, but not as good as Shell.
Certainly the Supermarket fuels did not produce as good results.

OK, I may sound sad, but I logged every litre of fuel for 13 years on the Landy, and run it through a spreadsheet.
I have never owned a vehicle that long before and the results were interesting to say the least.

Also I bought the Landy when it was 11 years old and used it as a daily drive for 13 year. It is happily residing in Fareham now owned by a friend. I sold it at 194k, and I know it has now gone well past 200k Miles and is still going strong.

My Mates dad set me going when he said he got a sustained 4mpg more on Shell in his Montego Countyrman (Perkins Diesel engined one).

So thats my 2 reils worth.

The answer to this question is one that I have recently found out through my farther in law whom deals with petro chemical companies through dispute resolution.

Shell, BP and other major oil suppliers do not sell their petrol to supermarkets.

Supermarkets buy a petrol chemical by-product given off during the distillation process like petrol (but is not) of which they add chemical / substance enhancers which replicate petrol's characteristics. It has slightly under performing and efficient characteristics to that of normal petrol sold by major oil and petrol suppliers.

A clear example of tesco was the silicon scare in March 2007 where silicon was found in Tesco and Morrision's "petrol":

http://news.bbc.co.uk/1/hi/uk/6413357.stm

Hope that answers the question

[Edited on 09/12/2007 by jnormandale]

[Edited on 09/12/2007 by jnormandale]

as above, I think the silicon incident proved once and for all that Shell, Esso etc are NOT using the same fuel as the supermarkets, despite the claims of others. Unless that is they would like to explain why only the supermarket fuel was contaminated....

I always use Shell when I can as I find it to be either the same price as local supermarkets or within 1p/litre. I used to have a SEAT Leon Cupra Turbo and it ran great on Optimax/V-Power and not so well on Tesco super unleaded or even BP Ultimate. I find that Shell petrol makes my car much smoother and my perception is certainly that I get more MPG. It is difficult to prove this since you can't drive the same journey in exactly the same way on two separate occasions.

I have records of all the fuel I have ever put in my Toyota Aygo since I bought it in May last year and I think if I correlate this with my credit card statements I should be able to determine where I bought the fuel. I might do a little spreadsheet exercise to see if there is any significant quantitative difference between suppliers although I'm not sure if I've bought in supermarket fuel since buying the car...

Just as I try to avoid buying groceries in a fuel station, I try to avoid buying fuel in a grocery shop...

If you want to see where each company gets its fuel then look at the following webpage. Click on each company in turn for details of where the fuel comes from:

http://www.petrolprices.com/fuel-companies.html

Cheers,
Craig.

A few years ago I was commuting in a Nova TD and found that the Shell super deisel whatever it was at the time was getting me better fuel consumption than the normal fuel, had to do the maths to work it out and it was good economics to buy the more expensive fuel.

As for why, I can only presume you get a better bang with non supermarket fuel

I was under the impression that the Supermarkets bought on the Open market probably in Holland.
The main difference with fuels are the addatives that are added before it is delivered to the pumps.

Also bear in mind that Shell Esso, Texaco, BP etc all have their own oil wells, ships, refineries, and retail outlets.
ie from the Well to the Pump they own and control the entire process.